In this class, we are often going to use VPython to create computational models, which will serve as a powerful tool to help us create visualizations and apply the ideas in this course to more real-world contexts. Below are some of the common Python commands that we will use in this course and some coding tips compiled by previous EMP-Cubed students.

Note: we do not expect you to have any coding experience prior to this course, and we will not expect you to write a program from scratch. We will primarily be asking you to interpret chunks of code with your group members and adjust/modify pieces of code that you will be given.

• Exponents
• Objects (box, sphere, arrow)
  • Object characteristics (pos, length, width, radius, color, etc)
• Vectors - vec()
• Magnitude - mag()
• Print - print()
• Dot Product - dot()
• Cross Product - cross()

• Check your parentheses - the computer will very strictly follow the order of operations (PEMDAS - Parentheses Exponents Multiplication Division Addition Subtraction). When writing out equations, make sure you have parentheses in the correct places. For example in the code below, the computer would say A = 6 but B = 4 - so these are not the same thing! Parentheses errors can be especially tricky because the program will likely run perfectly fine. Also, make sure that each of your parentheses match up – in other words every bracket has to have a buddy.

A=4+4/2
B=(4+4)/2

• Watch upper/lower cases - coding is case sensitive - meaning that lowercase and uppercase letters mean something different in coding. If I had two different variables named Num_1 and num_1, Python would treat these as two distinct objects. If you initially set your variable name to be Num_1 but wrote num_1 throughout the rest of your code, Python would not know what num_1 was. Just be conscious that when you are naming or using different elements in your code, that you are writing it the same way every time.
• Watch whitespace
• Comments